Removal of paints, varnishes, etc.



WILLIAM TIDDY, OF NORRISTOWN, PENNSYLVANIA, ASSIGNOR TO RAINEY-WOOI) COKE COMPANY, OF NEW YORK, N. Y.

, A CORPORATION OF PENNSYLVANIA.

REMOVAL OF PAINTS, VABNISHES, ETC.

No Drawing.

To all whom it may concern:

Be it known that I, WILLIAM TmnY, a subject of the King of Great Britain, residing at Norris'town, in the county of Montgomery, State of Pennsylvania, have 1nvented certain new and useful Improvements in the Removal of Paints, varnishes, Etc; and I do hereby declare the following to be a full, clear, andv exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to'improvements 1n 3 the removal of paints, varnishes, enamels,

etc., and includes an improved method of removing paints and similar materials, as well as improved compositions adapted for such use.

The invention is based upon the discovery that paints, varnishes, etc., can be removed in a simple and advantageous manner by the application thereto of the heavy basic oils from coal tar which contain the heavier bases, of higher boiling point than pyridin.

In the recovery-of pyridin bases from coal tar or from coal tar fractions or distillates, or from saturator liquor, a mixture of various bases is obtained, probably consisting largely, or for the most part, of pyridin bases, The lighter boiling fractions of these bases are more readily volatile and have an unpleasant and objectionable penetrative odor. I have found, however, that if the heavier bases or basic oils are freed from the more readily volatile constituents, such as pyridin, and the fraction commonly separated as commercial pyridin, the remaining heavy bases are relatively free from the objections above mentioned and form a valu-' able material for use as paint, varnish, etc., removers, inasmuch as they readily remove paint, varnish, etc., from metals, wood and rubber, Without damage'to the cleaned material.

The heavy pyridin bases can thus be used, for example, for the removal of white or colored enamel from metal surfaces, for the removal .of paint from wood, metal, or other surfaces, for the removal of varnish and shellac, etc., from old woodwork, for the removal of tar and oil from rubber tires, etc.

The heavy bases that are used, according to the present invention, can be obtained by fractionation 'or rectification of the pyridin Specification of Letters Patent.

Application filed- May 19,

Patented May 30, 192 2.

1921. Serial No. 470,971.

bases from coal tar, such as are obtained, for example, from treating various coal tar distlllates orproducts with acid, etc. By carrying out the distillation with a suitable dephlegmator, substantially all of the lower boiling constituents, boiling below 160 0., can be readlly removed, and, by their removal, the remaining heavy bases or-basio o ls can be substantially free from object onable and unpleasant penetrative odor. I have thus used to advantage a heavy basic Oll, obtained from pyridin bases, the greater portion of which boils between 160 and 194 C., for example, 50% boiling at 182 C. and 90% at 194 C.,.and with only a very small percentage boiling below 160 0., e. g., 5%, or less.

The heavy bases thus produced can advantageously be used without any admixture as they readily attack the paint or varnish, etc., Without injury to the wood or metal surfaces. I have found, however, that only a very small amount of the material is necessary, for example, such as is obtained by applying a thin coat of the heavy bases to the painted or varnished surface, and that an increased amount of the pyridin bases may even be less advantageous in bringing about the desired removal of the paint or varnish layer. 7

For some purposes, however, the heavy bases may volatilize to an objectionable degree, even though they are free from the more readily volatile pyridin fraction, particularly when used in hot weather or in a heated atmosphere. The heavy bases can be advantageously improved, to overcome this objection, by incorporating therewith various thickening agents which retard the volatilization or evaporation of the basic oils. Various thickeners or retarders can thus be used, which will advantageously modify the action of the heavy basic oils when used for the removal of paint, etc. The thickeners may be such as will dissolve in the basic oils, and will thus increase their consistency, or they may be materials which will remain in suspension in the oils, for example, substances of like specific gravity which will remain in suspension without any considerable tendency to settle out. Certain inorganic substances, such as certain forms of calcium carbonate, have substantially the same specific gravity as the basic oils, and, when incorporated therewith, readily remain in suspension, and thus thicken and modify the composition and retard its tendency to volatilize until it has exerted-the desired action in attacking the paint or varnish that may have to be removed.

, A paint remover composition of improved.

or modified properties can be produced by compounding with the heavy pyrldm bases other constituents which are solvents for the paint or varnish film, in whole or in part, or which serve to modify and regulate the solvent action of the pyridin bases themselves. Oils, fats, waxes, etc., of various kinds can thus be compounded with the pyridin bases, in varying proportions, as well as petroleum or coaltar hydrocarbons, alcohols, phenols, etc.

I claim: I

1. The method of removing paints,varnishes, etc., which comprises treating the same with heavy bases from coal tar, which bases are substantially free from pyridin.

2. The method of removing paints,-varnishes, etc., which comprises treating the ing same with heavy coal tar bases having a boilin point substantially above 160 (J- 3. 'f he method of removing paints, var

nishes, etc., which comprises treating the .same with a composition containing heavy bases from coal tar which are substantially free from pyridin, together with a thicken- WILLIAM TIDDY. 

